There are certain advantages to be gained by employing rotary cutters to accomplish the mowing function as opposed to employing reciprocating sickles, for example. There are, however, certain disadvantages as well, among these being the vulnerability of the mowing rotors to damage due to impacts with obstacles such as stumps, dirt mounds, and stones. Furthermore, in the formation of windrows using rotary mowers, it has heretofore been thought necessary to utilize a pair of cooperating, upright drums counterrotating in such a way that the mowed crops are engaged by the drums and flung rearwardly in a converged path of travel for subsequent deposit on the ground in a windrow.